Improvement in duplex wrench



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` AUGUSTUS BALLDAvIs,` or PHILADELPHIA, PnNNsvLvANtA,

Letters Patent No.4 106,129, dated Lug/,ust 9; 1870.

IMPROVEMENT IN DUPLEX WRENCH.

The ASczhecmlelreferrecl to in these Letters Patentand making part of the same I, AUGUSTUS" Bann DAvIs. of Philadelphia, countyof Philadelphia, State of Pemisylvania, have in of' the movablev jaw, for the purpose of' imparting strength to' the same.

Second, of a nut adapted to the screw-stein of the wrench, and confined between a rounded top and bottom of a recess formed in the movable jaw, so that the said nut may not interfere with the free pla-y of the jaw, as fully explained hereafter.

' Third, of the combination of a serrated or toothed zportion of the permanentjaw with a plain inclined portion of the movable jaw, so that a round object can be more firmly griped than by the jaws described' in my aforesaid patent.

Dcscriptfionof the Accompany-ag Drawing. Figure 1 is a perspective view of my improved wrench; Figure 2, anedge view "Figure 3, aside view, partly in section; `I `igure 4, a sectional plan, ou the line 1 2, iig. 3 jFigure 5, a perspective view of the movable jawv of the wrench.; and

Figure 6, a sectional plan, illustrating a modification of part lof my invention.

General-Description. A is the stem of the-wrench; B, thebandle D, the permanent jaw; and l I the movable jaw. i

Uu the rounded edges of thellat stem is formed a i Vscrew-tlnead adapted to a nntgf, which is confined make the jaw witha thin web, w, oneach side, so as to form a hollow-"box-like casting, the webs, although conlparat-ively light, affording the most efficient medium, and the most advantageous disposal of metal,

for resisting the strains to which the jawhas' to be subjected.

The webs w lw maybe lightened byholes, nl', of any desired shape; or the jaw may be rendered lighter by au opening, n, in one edge, as shown in fig. 5; or there may be a web, zo',on one side only, as shown in fig. 6, the opposite side of the jaw being entirely open, or having simple strengthening-ribs, fu; or the upper and lower ends of the jawmay be connected together' j by two webs, between which intervenes a clear open space.

The movable jaw is so adapted 'to the screw-stem A as to slide freely thereon without any lateral play, but so that the jaw may have a slight longitudinal play below on the stem, and' more play above, as best observed on reference to fig. 3.

A pocket is formed within the movable jaw, for the reception of a spiral spring, f, which, bearingr aga-inst a small pin, h, forces the latter against oneedgc of the screw-stem A, and tends to maintain the opposite edge in contact with the end p of the slot q in the top of ,the jaw, the slot being' of "suflicient length to per- -mit a limited longitudinal play or vibration of thel jaw on the stem. The freedom of this play is in no way interfered with by the nut F, owing to the rounded top and bottom, a: rv, of the opening within which the nut is confined.

The portion c ofthe permanent jaw, and the por: tion e of the movable jaw, constitute that part of the wrench which` is adapted to ordinary nuts, screwheads, and other square or many-sided objects, while the portion t' of the permanent jaw, and the portioni `ofthemovable jaw, are devoted to round objects,

such as pipes, rods, Snc.

v On applying this portion of the instrument to the round rod j, and moving the handle in the direction of the arrowl, gf 3, the lower jaw will be moved in the directionfof the arrow 2, while the rod is firmly jammedbetween-the serrated under side of the 'portion i of the permanent liaw D and the. inclined upper edge of -the portion t ofthe movable ja'w E, after which the wrench cannot be moved further in the direction -of the arrow 1 without turning the saidrod j.

ln my former patent, both the under side of the permanent jaw and the upper inclined side of the movable jaw were shown and described as notched or serrated but I have found in practice that a much more perfect gripe can be obtained by forming inclined teeth on the underside of the upper jaw only, the inclined upper side ofthe movable jaw being perfectly plain. It is important, however, that the sex-rations the stem with the permanent jaw. This defect I overcome by means of' :t fillet, t, fig. 3, which affords the desired strength without interfering with theeffective operation of the instrument on round rods, pipes, Saez, and without rendering the instrument heavy and clumsy.

A recess, tf, is mede in the upper end ofthe movalil'e jaw, for receiving the whole or a. portion of this Het.

Additional strength ml'tyhe imparted to the stem nt'its junction with the'permzment jaw, by a. fillet, y, on euch side of the stem, the slot in the upper part of the movable j nw being countersunk to receive'tbese iillets.

la'ims. 1. The vibrating and sliding jaw E, having on one or both sides a. thin web, as set forth.

2. A nut, F, adapted to the screw-stem'A, and con fined between the rounded top angl bottom, x x, of n. recess in the movable jnwE, ns specified;

nesses. Y

AUGUSTUS BALL DAVIS.

Witnesses z l WM. A. Smm., HARRY SMITH.

3. The combination of the serrated or toothed por- 

